1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPV4 GSO/GRO offload support 4 * Linux INET implementation 5 * 6 * UDPv4 GSO support 7 */ 8 9 #include <linux/skbuff.h> 10 #include <net/gro.h> 11 #include <net/gso.h> 12 #include <net/udp.h> 13 #include <net/protocol.h> 14 #include <net/inet_common.h> 15 __skb_udp_tunnel_segment(struct sk_buff * skb,netdev_features_t features,struct sk_buff * (* gso_inner_segment)(struct sk_buff * skb,netdev_features_t features),__be16 new_protocol,bool is_ipv6)16 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, 17 netdev_features_t features, 18 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 19 netdev_features_t features), 20 __be16 new_protocol, bool is_ipv6) 21 { 22 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 23 bool remcsum, need_csum, offload_csum, gso_partial; 24 struct sk_buff *segs = ERR_PTR(-EINVAL); 25 struct udphdr *uh = udp_hdr(skb); 26 u16 mac_offset = skb->mac_header; 27 __be16 protocol = skb->protocol; 28 u16 mac_len = skb->mac_len; 29 int udp_offset, outer_hlen; 30 __wsum partial; 31 bool need_ipsec; 32 33 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 34 goto out; 35 36 /* Adjust partial header checksum to negate old length. 37 * We cannot rely on the value contained in uh->len as it is 38 * possible that the actual value exceeds the boundaries of the 39 * 16 bit length field due to the header being added outside of an 40 * IP or IPv6 frame that was already limited to 64K - 1. 41 */ 42 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) 43 partial = (__force __wsum)uh->len; 44 else 45 partial = (__force __wsum)htonl(skb->len); 46 partial = csum_sub(csum_unfold(uh->check), partial); 47 48 /* setup inner skb. */ 49 skb->encapsulation = 0; 50 SKB_GSO_CB(skb)->encap_level = 0; 51 __skb_pull(skb, tnl_hlen); 52 skb_reset_mac_header(skb); 53 skb_set_network_header(skb, skb_inner_network_offset(skb)); 54 skb_set_transport_header(skb, skb_inner_transport_offset(skb)); 55 skb->mac_len = skb_inner_network_offset(skb); 56 skb->protocol = new_protocol; 57 58 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); 59 skb->encap_hdr_csum = need_csum; 60 61 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); 62 skb->remcsum_offload = remcsum; 63 64 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); 65 /* Try to offload checksum if possible */ 66 offload_csum = !!(need_csum && 67 !need_ipsec && 68 (skb->dev->features & 69 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : 70 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); 71 72 features &= skb->dev->hw_enc_features; 73 if (need_csum) 74 features &= ~NETIF_F_SCTP_CRC; 75 76 /* The only checksum offload we care about from here on out is the 77 * outer one so strip the existing checksum feature flags and 78 * instead set the flag based on our outer checksum offload value. 79 */ 80 if (remcsum) { 81 features &= ~NETIF_F_CSUM_MASK; 82 if (!need_csum || offload_csum) 83 features |= NETIF_F_HW_CSUM; 84 } 85 86 /* segment inner packet. */ 87 segs = gso_inner_segment(skb, features); 88 if (IS_ERR_OR_NULL(segs)) { 89 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, 90 mac_len); 91 goto out; 92 } 93 94 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 95 96 outer_hlen = skb_tnl_header_len(skb); 97 udp_offset = outer_hlen - tnl_hlen; 98 skb = segs; 99 do { 100 unsigned int len; 101 102 if (remcsum) 103 skb->ip_summed = CHECKSUM_NONE; 104 105 /* Set up inner headers if we are offloading inner checksum */ 106 if (skb->ip_summed == CHECKSUM_PARTIAL) { 107 skb_reset_inner_headers(skb); 108 skb->encapsulation = 1; 109 } 110 111 skb->mac_len = mac_len; 112 skb->protocol = protocol; 113 114 __skb_push(skb, outer_hlen); 115 skb_reset_mac_header(skb); 116 skb_set_network_header(skb, mac_len); 117 skb_set_transport_header(skb, udp_offset); 118 len = skb->len - udp_offset; 119 uh = udp_hdr(skb); 120 121 /* If we are only performing partial GSO the inner header 122 * will be using a length value equal to only one MSS sized 123 * segment instead of the entire frame. 124 */ 125 if (gso_partial && skb_is_gso(skb)) { 126 uh->len = htons(skb_shinfo(skb)->gso_size + 127 SKB_GSO_CB(skb)->data_offset + 128 skb->head - (unsigned char *)uh); 129 } else { 130 uh->len = htons(len); 131 } 132 133 if (!need_csum) 134 continue; 135 136 uh->check = ~csum_fold(csum_add(partial, 137 (__force __wsum)htonl(len))); 138 139 if (skb->encapsulation || !offload_csum) { 140 uh->check = gso_make_checksum(skb, ~uh->check); 141 if (uh->check == 0) 142 uh->check = CSUM_MANGLED_0; 143 } else { 144 skb->ip_summed = CHECKSUM_PARTIAL; 145 skb->csum_start = skb_transport_header(skb) - skb->head; 146 skb->csum_offset = offsetof(struct udphdr, check); 147 } 148 } while ((skb = skb->next)); 149 out: 150 return segs; 151 } 152 skb_udp_tunnel_segment(struct sk_buff * skb,netdev_features_t features,bool is_ipv6)153 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 154 netdev_features_t features, 155 bool is_ipv6) 156 { 157 const struct net_offload __rcu **offloads; 158 __be16 protocol = skb->protocol; 159 const struct net_offload *ops; 160 struct sk_buff *segs = ERR_PTR(-EINVAL); 161 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 162 netdev_features_t features); 163 164 rcu_read_lock(); 165 166 switch (skb->inner_protocol_type) { 167 case ENCAP_TYPE_ETHER: 168 protocol = skb->inner_protocol; 169 gso_inner_segment = skb_mac_gso_segment; 170 break; 171 case ENCAP_TYPE_IPPROTO: 172 offloads = is_ipv6 ? inet6_offloads : inet_offloads; 173 ops = rcu_dereference(offloads[skb->inner_ipproto]); 174 if (!ops || !ops->callbacks.gso_segment) 175 goto out_unlock; 176 gso_inner_segment = ops->callbacks.gso_segment; 177 break; 178 default: 179 goto out_unlock; 180 } 181 182 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, 183 protocol, is_ipv6); 184 185 out_unlock: 186 rcu_read_unlock(); 187 188 return segs; 189 } 190 EXPORT_SYMBOL(skb_udp_tunnel_segment); 191 __udpv4_gso_segment_csum(struct sk_buff * seg,__be32 * oldip,__be32 * newip,__be16 * oldport,__be16 * newport)192 static void __udpv4_gso_segment_csum(struct sk_buff *seg, 193 __be32 *oldip, __be32 *newip, 194 __be16 *oldport, __be16 *newport) 195 { 196 struct udphdr *uh; 197 struct iphdr *iph; 198 199 if (*oldip == *newip && *oldport == *newport) 200 return; 201 202 uh = udp_hdr(seg); 203 iph = ip_hdr(seg); 204 205 if (uh->check) { 206 inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, 207 true); 208 inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, 209 false); 210 if (!uh->check) 211 uh->check = CSUM_MANGLED_0; 212 } 213 *oldport = *newport; 214 215 csum_replace4(&iph->check, *oldip, *newip); 216 *oldip = *newip; 217 } 218 __udpv4_gso_segment_list_csum(struct sk_buff * segs)219 static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) 220 { 221 struct sk_buff *seg; 222 struct udphdr *uh, *uh2; 223 struct iphdr *iph, *iph2; 224 225 seg = segs; 226 uh = udp_hdr(seg); 227 iph = ip_hdr(seg); 228 229 if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && 230 (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && 231 (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && 232 (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) 233 return segs; 234 235 while ((seg = seg->next)) { 236 uh2 = udp_hdr(seg); 237 iph2 = ip_hdr(seg); 238 239 __udpv4_gso_segment_csum(seg, 240 &iph2->saddr, &iph->saddr, 241 &uh2->source, &uh->source); 242 __udpv4_gso_segment_csum(seg, 243 &iph2->daddr, &iph->daddr, 244 &uh2->dest, &uh->dest); 245 } 246 247 return segs; 248 } 249 __udp_gso_segment_list(struct sk_buff * skb,netdev_features_t features,bool is_ipv6)250 static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, 251 netdev_features_t features, 252 bool is_ipv6) 253 { 254 unsigned int mss = skb_shinfo(skb)->gso_size; 255 256 skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); 257 if (IS_ERR(skb)) 258 return skb; 259 260 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); 261 262 return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); 263 } 264 __udp_gso_segment(struct sk_buff * gso_skb,netdev_features_t features,bool is_ipv6)265 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 266 netdev_features_t features, bool is_ipv6) 267 { 268 struct sock *sk = gso_skb->sk; 269 unsigned int sum_truesize = 0; 270 struct sk_buff *segs, *seg; 271 struct udphdr *uh; 272 unsigned int mss; 273 bool copy_dtor; 274 __sum16 check; 275 __be16 newlen; 276 277 mss = skb_shinfo(gso_skb)->gso_size; 278 if (gso_skb->len <= sizeof(*uh) + mss) 279 return ERR_PTR(-EINVAL); 280 281 if (unlikely(skb_checksum_start(gso_skb) != 282 skb_transport_header(gso_skb) && 283 !(skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST))) 284 return ERR_PTR(-EINVAL); 285 286 /* We don't know if egress device can segment and checksum the packet 287 * when IPv6 extension headers are present. Fall back to software GSO. 288 */ 289 if (gso_skb->ip_summed != CHECKSUM_PARTIAL) 290 features &= ~(NETIF_F_GSO_UDP_L4 | NETIF_F_CSUM_MASK); 291 292 if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) { 293 /* Packet is from an untrusted source, reset gso_segs. */ 294 skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh), 295 mss); 296 return NULL; 297 } 298 299 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) { 300 /* Detect modified geometry and pass those to skb_segment. */ 301 if (skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size) 302 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 303 304 /* Setup csum, as fraglist skips this in udp4_gro_receive. */ 305 gso_skb->csum_start = skb_transport_header(gso_skb) - gso_skb->head; 306 gso_skb->csum_offset = offsetof(struct udphdr, check); 307 gso_skb->ip_summed = CHECKSUM_PARTIAL; 308 309 uh = udp_hdr(gso_skb); 310 if (is_ipv6) 311 uh->check = ~udp_v6_check(gso_skb->len, 312 &ipv6_hdr(gso_skb)->saddr, 313 &ipv6_hdr(gso_skb)->daddr, 0); 314 else 315 uh->check = ~udp_v4_check(gso_skb->len, 316 ip_hdr(gso_skb)->saddr, 317 ip_hdr(gso_skb)->daddr, 0); 318 } 319 320 skb_pull(gso_skb, sizeof(*uh)); 321 322 /* clear destructor to avoid skb_segment assigning it to tail */ 323 copy_dtor = gso_skb->destructor == sock_wfree; 324 if (copy_dtor) 325 gso_skb->destructor = NULL; 326 327 segs = skb_segment(gso_skb, features); 328 if (IS_ERR_OR_NULL(segs)) { 329 if (copy_dtor) 330 gso_skb->destructor = sock_wfree; 331 return segs; 332 } 333 334 /* GSO partial and frag_list segmentation only requires splitting 335 * the frame into an MSS multiple and possibly a remainder, both 336 * cases return a GSO skb. So update the mss now. 337 */ 338 if (skb_is_gso(segs)) 339 mss *= skb_shinfo(segs)->gso_segs; 340 341 seg = segs; 342 uh = udp_hdr(seg); 343 344 /* preserve TX timestamp flags and TS key for first segment */ 345 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 346 skb_shinfo(seg)->tx_flags |= 347 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 348 349 /* compute checksum adjustment based on old length versus new */ 350 newlen = htons(sizeof(*uh) + mss); 351 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 352 353 for (;;) { 354 if (copy_dtor) { 355 seg->destructor = sock_wfree; 356 seg->sk = sk; 357 sum_truesize += seg->truesize; 358 } 359 360 if (!seg->next) 361 break; 362 363 uh->len = newlen; 364 uh->check = check; 365 366 if (seg->ip_summed == CHECKSUM_PARTIAL) 367 gso_reset_checksum(seg, ~check); 368 else 369 uh->check = gso_make_checksum(seg, ~check) ? : 370 CSUM_MANGLED_0; 371 372 seg = seg->next; 373 uh = udp_hdr(seg); 374 } 375 376 /* last packet can be partial gso_size, account for that in checksum */ 377 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 378 seg->data_len); 379 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 380 381 uh->len = newlen; 382 uh->check = check; 383 384 if (seg->ip_summed == CHECKSUM_PARTIAL) 385 gso_reset_checksum(seg, ~check); 386 else 387 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 388 389 /* On the TX path, CHECKSUM_NONE and CHECKSUM_UNNECESSARY have the same 390 * meaning. However, check for bad offloads in the GSO stack expects the 391 * latter, if the checksum was calculated in software. To vouch for the 392 * segment skbs we actually need to set it on the gso_skb. 393 */ 394 if (gso_skb->ip_summed == CHECKSUM_NONE) 395 gso_skb->ip_summed = CHECKSUM_UNNECESSARY; 396 397 /* update refcount for the packet */ 398 if (copy_dtor) { 399 int delta = sum_truesize - gso_skb->truesize; 400 401 /* In some pathological cases, delta can be negative. 402 * We need to either use refcount_add() or refcount_sub_and_test() 403 */ 404 if (likely(delta >= 0)) 405 refcount_add(delta, &sk->sk_wmem_alloc); 406 else 407 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 408 } 409 return segs; 410 } 411 EXPORT_SYMBOL_GPL(__udp_gso_segment); 412 udp4_ufo_fragment(struct sk_buff * skb,netdev_features_t features)413 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 414 netdev_features_t features) 415 { 416 struct sk_buff *segs = ERR_PTR(-EINVAL); 417 unsigned int mss; 418 __wsum csum; 419 struct udphdr *uh; 420 struct iphdr *iph; 421 422 if (skb->encapsulation && 423 (skb_shinfo(skb)->gso_type & 424 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 425 segs = skb_udp_tunnel_segment(skb, features, false); 426 goto out; 427 } 428 429 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 430 goto out; 431 432 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 433 goto out; 434 435 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 436 return __udp_gso_segment(skb, features, false); 437 438 mss = skb_shinfo(skb)->gso_size; 439 if (unlikely(skb->len <= mss)) 440 goto out; 441 442 /* Do software UFO. Complete and fill in the UDP checksum as 443 * HW cannot do checksum of UDP packets sent as multiple 444 * IP fragments. 445 */ 446 447 uh = udp_hdr(skb); 448 iph = ip_hdr(skb); 449 450 uh->check = 0; 451 csum = skb_checksum(skb, 0, skb->len, 0); 452 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 453 if (uh->check == 0) 454 uh->check = CSUM_MANGLED_0; 455 456 skb->ip_summed = CHECKSUM_UNNECESSARY; 457 458 /* If there is no outer header we can fake a checksum offload 459 * due to the fact that we have already done the checksum in 460 * software prior to segmenting the frame. 461 */ 462 if (!skb->encap_hdr_csum) 463 features |= NETIF_F_HW_CSUM; 464 465 /* Fragment the skb. IP headers of the fragments are updated in 466 * inet_gso_segment() 467 */ 468 segs = skb_segment(skb, features); 469 out: 470 return segs; 471 } 472 473 474 #define UDP_GRO_CNT_MAX 64 udp_gro_receive_segment(struct list_head * head,struct sk_buff * skb)475 static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 476 struct sk_buff *skb) 477 { 478 struct udphdr *uh = udp_gro_udphdr(skb); 479 struct sk_buff *pp = NULL; 480 struct udphdr *uh2; 481 struct sk_buff *p; 482 unsigned int ulen; 483 int ret = 0; 484 int flush; 485 486 /* requires non zero csum, for symmetry with GSO */ 487 if (!uh->check) { 488 NAPI_GRO_CB(skb)->flush = 1; 489 return NULL; 490 } 491 492 /* Do not deal with padded or malicious packets, sorry ! */ 493 ulen = ntohs(uh->len); 494 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 495 NAPI_GRO_CB(skb)->flush = 1; 496 return NULL; 497 } 498 /* pull encapsulating udp header */ 499 skb_gro_pull(skb, sizeof(struct udphdr)); 500 501 list_for_each_entry(p, head, list) { 502 if (!NAPI_GRO_CB(p)->same_flow) 503 continue; 504 505 uh2 = udp_hdr(p); 506 507 /* Match ports only, as csum is always non zero */ 508 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 509 NAPI_GRO_CB(p)->same_flow = 0; 510 continue; 511 } 512 513 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 514 NAPI_GRO_CB(skb)->flush = 1; 515 return p; 516 } 517 518 flush = gro_receive_network_flush(uh, uh2, p); 519 520 /* Terminate the flow on len mismatch or if it grow "too much". 521 * Under small packet flood GRO count could elsewhere grow a lot 522 * leading to excessive truesize values. 523 * On len mismatch merge the first packet shorter than gso_size, 524 * otherwise complete the GRO packet. 525 */ 526 if (ulen > ntohs(uh2->len) || flush) { 527 pp = p; 528 } else { 529 if (NAPI_GRO_CB(skb)->is_flist) { 530 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 531 NAPI_GRO_CB(skb)->flush = 1; 532 return NULL; 533 } 534 if ((skb->ip_summed != p->ip_summed) || 535 (skb->csum_level != p->csum_level)) { 536 NAPI_GRO_CB(skb)->flush = 1; 537 return NULL; 538 } 539 ret = skb_gro_receive_list(p, skb); 540 } else { 541 skb_gro_postpull_rcsum(skb, uh, 542 sizeof(struct udphdr)); 543 544 ret = skb_gro_receive(p, skb); 545 } 546 } 547 548 if (ret || ulen != ntohs(uh2->len) || 549 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 550 pp = p; 551 552 return pp; 553 } 554 555 /* mismatch, but we never need to flush */ 556 return NULL; 557 } 558 udp_gro_receive(struct list_head * head,struct sk_buff * skb,struct udphdr * uh,struct sock * sk)559 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 560 struct udphdr *uh, struct sock *sk) 561 { 562 struct sk_buff *pp = NULL; 563 struct sk_buff *p; 564 struct udphdr *uh2; 565 unsigned int off = skb_gro_offset(skb); 566 int flush = 1; 567 568 /* We can do L4 aggregation only if the packet can't land in a tunnel 569 * otherwise we could corrupt the inner stream. Detecting such packets 570 * cannot be foolproof and the aggregation might still happen in some 571 * cases. Such packets should be caught in udp_unexpected_gso later. 572 */ 573 NAPI_GRO_CB(skb)->is_flist = 0; 574 if (!sk || !udp_sk(sk)->gro_receive) { 575 /* If the packet was locally encapsulated in a UDP tunnel that 576 * wasn't detected above, do not GRO. 577 */ 578 if (skb->encapsulation) 579 goto out; 580 581 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 582 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1; 583 584 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 585 (sk && udp_test_bit(GRO_ENABLED, sk)) || NAPI_GRO_CB(skb)->is_flist) 586 return call_gro_receive(udp_gro_receive_segment, head, skb); 587 588 /* no GRO, be sure flush the current packet */ 589 goto out; 590 } 591 592 if (NAPI_GRO_CB(skb)->encap_mark || 593 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 594 NAPI_GRO_CB(skb)->csum_cnt == 0 && 595 !NAPI_GRO_CB(skb)->csum_valid)) 596 goto out; 597 598 /* mark that this skb passed once through the tunnel gro layer */ 599 NAPI_GRO_CB(skb)->encap_mark = 1; 600 601 flush = 0; 602 603 list_for_each_entry(p, head, list) { 604 if (!NAPI_GRO_CB(p)->same_flow) 605 continue; 606 607 uh2 = (struct udphdr *)(p->data + off); 608 609 /* Match ports and either checksums are either both zero 610 * or nonzero. 611 */ 612 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 613 (!uh->check ^ !uh2->check)) { 614 NAPI_GRO_CB(p)->same_flow = 0; 615 continue; 616 } 617 } 618 619 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 620 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 621 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 622 623 out: 624 skb_gro_flush_final(skb, pp, flush); 625 return pp; 626 } 627 EXPORT_SYMBOL(udp_gro_receive); 628 udp4_gro_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport)629 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 630 __be16 dport) 631 { 632 const struct iphdr *iph = skb_gro_network_header(skb); 633 struct net *net = dev_net(skb->dev); 634 int iif, sdif; 635 636 inet_get_iif_sdif(skb, &iif, &sdif); 637 638 return __udp4_lib_lookup(net, iph->saddr, sport, 639 iph->daddr, dport, iif, 640 sdif, net->ipv4.udp_table, NULL); 641 } 642 643 INDIRECT_CALLABLE_SCOPE udp4_gro_receive(struct list_head * head,struct sk_buff * skb)644 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 645 { 646 struct udphdr *uh = udp_gro_udphdr(skb); 647 struct sock *sk = NULL; 648 struct sk_buff *pp; 649 650 if (unlikely(!uh)) 651 goto flush; 652 653 /* Don't bother verifying checksum if we're going to flush anyway. */ 654 if (NAPI_GRO_CB(skb)->flush) 655 goto skip; 656 657 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 658 inet_gro_compute_pseudo)) 659 goto flush; 660 else if (uh->check) 661 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 662 inet_gro_compute_pseudo); 663 skip: 664 NAPI_GRO_CB(skb)->is_ipv6 = 0; 665 666 if (static_branch_unlikely(&udp_encap_needed_key)) 667 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 668 669 pp = udp_gro_receive(head, skb, uh, sk); 670 return pp; 671 672 flush: 673 NAPI_GRO_CB(skb)->flush = 1; 674 return NULL; 675 } 676 udp_gro_complete_segment(struct sk_buff * skb)677 static int udp_gro_complete_segment(struct sk_buff *skb) 678 { 679 struct udphdr *uh = udp_hdr(skb); 680 681 skb->csum_start = (unsigned char *)uh - skb->head; 682 skb->csum_offset = offsetof(struct udphdr, check); 683 skb->ip_summed = CHECKSUM_PARTIAL; 684 685 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 686 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 687 688 if (skb->encapsulation) 689 skb->inner_transport_header = skb->transport_header; 690 691 return 0; 692 } 693 udp_gro_complete(struct sk_buff * skb,int nhoff,udp_lookup_t lookup)694 int udp_gro_complete(struct sk_buff *skb, int nhoff, 695 udp_lookup_t lookup) 696 { 697 __be16 newlen = htons(skb->len - nhoff); 698 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 699 struct sock *sk; 700 int err; 701 702 uh->len = newlen; 703 704 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 705 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 706 if (sk && udp_sk(sk)->gro_complete) { 707 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 708 : SKB_GSO_UDP_TUNNEL; 709 710 /* clear the encap mark, so that inner frag_list gro_complete 711 * can take place 712 */ 713 NAPI_GRO_CB(skb)->encap_mark = 0; 714 715 /* Set encapsulation before calling into inner gro_complete() 716 * functions to make them set up the inner offsets. 717 */ 718 skb->encapsulation = 1; 719 err = udp_sk(sk)->gro_complete(sk, skb, 720 nhoff + sizeof(struct udphdr)); 721 } else { 722 err = udp_gro_complete_segment(skb); 723 } 724 725 if (skb->remcsum_offload) 726 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 727 728 return err; 729 } 730 EXPORT_SYMBOL(udp_gro_complete); 731 udp4_gro_complete(struct sk_buff * skb,int nhoff)732 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 733 { 734 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation]; 735 const struct iphdr *iph = (struct iphdr *)(skb->data + offset); 736 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 737 738 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 739 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 740 uh->len = htons(skb->len - nhoff); 741 742 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 743 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 744 745 __skb_incr_checksum_unnecessary(skb); 746 747 return 0; 748 } 749 750 if (uh->check) 751 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 752 iph->daddr, 0); 753 754 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 755 } 756 udpv4_offload_init(void)757 int __init udpv4_offload_init(void) 758 { 759 net_hotdata.udpv4_offload = (struct net_offload) { 760 .callbacks = { 761 .gso_segment = udp4_ufo_fragment, 762 .gro_receive = udp4_gro_receive, 763 .gro_complete = udp4_gro_complete, 764 }, 765 }; 766 return inet_add_offload(&net_hotdata.udpv4_offload, IPPROTO_UDP); 767 } 768